An electro-optical modulator may be used for converting electrical signals into optical signals. Therein, analogue or digital electrical signals may be input to the electro-optical modulator and the electro-optical modulator may then output corresponding optical signals. The optical signals in a form of amplitude or phase modulated light may then e.g. be transmitted through optical fibres. In order to enable data transmission at e.g. more than one gigabit per second (Gbps), the electro-optical modulator should be able to convert signals in a radiofrequency (RF) range.
Various types of electro-optical modulators have been proposed. High data transmission rates have been realized with a depletion type plasma modulator with pn-diodes as well as with an accumulation type plasma modulator with semiconductor-insulator-semiconductor capacitors, based on a Mach-Zehnder interferometer (MZI) architecture in push-pull configuration.
However, conventional electro-optical modulators of that type may suffer from cross-talk between neighbouring signal lines in the push-pull configuration. Furthermore, in order to e.g. limit such cross-talk, such electro-optical modulators may need significant space so as to provide sufficient distance between the signal lines, thereby reducing a possible on-chip device density when a plurality of modulators is to be integrated within a single chip. Additionally, insufficient electro-magnetic shielding provisions may result in signal losses in transmission lines of the electro-optical modulator. And, last but not least, complex electro-magnetic shielding provisions and high data transmission requirements may result in high fabrication costs.